Moisture-curable polyolefin pressure-sensitive adhesive
AssigneeMinnesota Mining and Manufacturing Company
InventorsGaddam N. Babu, James R. Peterson, Sehyun Nam
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Abstract
A pressure-sensitive adhesive comprises a moisture-curable polymer comprising a polymer prepared by polymerization of at least one .alpha.-olefin monomer, said polymer containing hydrolyzable or condensable silyl groups and having a weight average molecular weight of at least 30,000. The pressure-sensitive adhesive can be hot-melt coated without emitting volatiles and then can adhere aggressively to both polar and nonpolar substrates. The PSA has good internal strength at high temperatures.
Claims12
A method of preparing a pressure-sensitive adhesive comprising the steps of
- a) polymerizing a C.sub.6 to C.sub.14 .alpha.-olefin monomer with a conjugated diene using Ziegler-Natta catalyst to produce a copolymer containing ethylenically-unsaturated chains,
- b) optionally, blending at least one of a hydrated salt and a tackifying agent with said copolymer, and
- c) in the presence of an effective amount of a hydrosilation catalyst, hydrosilating the ethylenic unsaturation with a hydrosilane of the formula HSiR.sub.p X.sub.(3-p) wherein
- R is a hydrocarbyl group selected from alkyl groups having 1 to 18 carbon atoms, aryl groups having 6 to 8 carbon atoms, and cycloalkyl groups having 5 to 8 carbon atoms;
- p is zero, one or two, and
- X is a hydrolyzable or condensable group selected from hydrogen, hydroxyl, hydrocarbyloxy, hydrocarbonyloxy, and halogen to produce a moisture-curable .alpha.-olefin polymer having a weight average molecular weight of at least 30,000.
A method of making a pressure-sensitive adhesive comprising the steps of
- polymerizing a C.sub.9 to C.sub.14 .alpha.-olefin monomer with a nonconjugated diene using Ziegler-Natta catalyst to produce a copolymer containing ethylenically-unsaturated chains,
- b) optionally, blending at least one of a hydrated salt and a tackifying agent with said copolymer, and
- c) in the presence of an effective amount of an initiator or by UV radiation in the presence of an effective amount of a photoinitiator, reacting the side chains with a mercaptoalkylalkoxysilane to produce a moisture-curable .alpha.-olefin polymer having a weight average molecular weight of at least 30,000.
A method of making a pressure-sensitive adhesive comprising the steps of
- a) polymerizing a C.sub.6 to C.sub.14 .alpha.-olefin monomer with a nonconjugated diene using an effective amount of a Ziegler-Natta catalyst to produce a copolymer containing ethylenically-unsaturated chains,
- b) optionally, blending at least one of a hydrated salt and a tackifying agent with said copolymer, and
- c) reacting the resulting .alpha.-olefin polymer with a hydrosilane in the presence of an effective amount of a hydrosilation catalyst to produce a moisture-curable .alpha.-olefin polymer having a weight average molecular weight of at least 30,000.
A method of making a pressure-sensitive adhesive comprising the steps of
- a) polymerizing a C.sub.6 to C.sub.14 .alpha.-olefin monomer alone or with an .alpha.-olefin monomer or with a nonconjugated diene using an effective amount of a Ziegler-Natta catalyst to product a homopolymer or a copolymer containing ethylenically-unsaturated chains,
- b) optionally, blending at least one of a hydrated salt and a tackifying agent with said copolymer.
- c) reacting the resulting .alpha.-olefin polymer with maleic anhydride in the presence of an effective amount of an initiator to produce an adduct, and
- d) reacting the maleated .alpha.-olefin polymer adduct with aminoalkylalkoxysilane or with isocyanatoalkylalkoxysilane to produce a moisture-curable .alpha.-olefin polymer having a weight average molecular weight of at least 30,000.
A method of making a pressure-sensitive adhesive comprising the steps of:
- a) polymerizing a C.sub.6 to C.sub.14 .alpha.-olefin monomer alone or with up to 40 mole % of one or more C.sub.2 to C.sub.5 .alpha.-olefin monomers using a Ziegler-Natta catalyst to produce a saturated homopolymer or a saturated or unsaturated copolymer,
- b) optionally, blending at least one of a hydrated salt with a tackifying agent with said copolymer,
- c) reacting maleic anhydride with aminoalkylalkoxysilane or with isocyanatoalkylalkoxysilane to produce imidoalkylalkoxysilane, and
- d) reacting the .alpha.-olefin polymer produced in step a) with the imidoalkoxysilane in the presence of an initiator to provide said pressure-sensitive adhesive.
Dependencies are inferred from the claim text.